Evaluación técnica del uso de hidrógeno gris en la Refinería La Libertad

Abstract

La Libertad Refinery (LLR) generates a significant amount of residual gas from its Parsons, Universal, and Cautivo distillation units. At present, this gas is routed to the Blow-down system and subsequently flared in the TEA, resulting in the loss of potential energy and contributing to pollutant emissions, particularly carbon dioxide and sulfur dioxide, associated with the combustion of Fuel Oil #4 in furnaces and boilers. This study evaluates the technical feasibility of utilizing this residual gas for gray hydrogen production through the Steam Methane Reforming (SMR) process. Based on documented technical antecedents, site visits, and operational data, a representative residual gas flow rate of 3.98 MMSCFD is adopted, with a methane-rich composition of 65%, consistent with values reported for refinery residual gases. Stoichiometric and energy balances were applied assuming an overall SMR efficiency of η = 70%, resulting in an estimated hydrogen production of approximately 17.79 t/d. These results correspond to model-based predictions, conditional upon the adopted gas composition and process efficiency assumptions, rather than direct plant measurements. The energy assessment indicates that the produced hydrogen could substitute approximately 38.39% of the current thermal demand supplied by Fuel Oil #4 in furnaces and boilers. In parallel, the environmental analysis projects potential reductions of about 51.02 t/month of SO₂ and 4,811.37 t/month of CO₂. Although the SMR process requires external heat input and presents a negative net energy balance, the valorization of residual gas represents a technically viable option to enhance refinery energy efficiency and reduce environmental impact Keywords: Gray hydrogen, steam methane reforming, residual gas, refineries, energy transition, Fuel Oil #4, emissions.